Transmission operating mechanism



Nov. 3, .1953 A. E. WILSON ET AL TRANSMISSION OPERATING MECHANISM 3Sheets-Sheet 1 Filed Sept. 11. 1944 w W m m T u? Z HM 05 "WW Z J Nov. 3,1953 A. E. WILSON ETAL TRANSMISSION OPERATING MECHANISM I5 Sheets-Sheet2 Filed Sept. 11, 1944 Tl m m m W m rm i mm M N i N 11 H OwWmQNQ \WQl Q,l/ QM I a m @LQQQ Ni \N\ i A. E. WILSON ET AL TRANSMISSION OPERATINGMECHANISM Nov. 3, 1953 3 Sheets-Sheet 5 Filed Sept. 11, 1944 PatentedNov. 3, 1953 TRANSMISSION OPERATING MECHANISM Albert E. Wilson, SouthBend, Ind., and Henry D'. Hukill, Cleveland, Ohio, assignors to BendixAviation Corporation, South Bend, Ind., a corporation of DelawareApplication September 11, 1944, Serial N 0. 553,524

7 Claims.

This invention relates in general to gear shifting mechanism and is ofparticular utility when employed in connection with speed-changing anddirection-reversing gearing commonly used in coupling the internalcombustion engine of an automotive vehicle or a tank with the drivingvehicle wheels or other propelling devices.

One object of our invention is to provide power means for operating atwo-speed transmission gear mechanism said mechanism being operablyassociated with a differential mechanism of standard construction andmounted adjacent thereto in the power plant of the vehicle. In otherwords, it is an object of our invention to provide power means foroperating the twospeed axle mechanism of the day.

Yet another object of our invention is to provide power means foroperating a two-speed axle said power means being controlledby an 7operation of the accelerator and an operation of a manually operatedselector valve.

A further object of our invention is to provide power means foroperating a change-speed transmission, such as the selective geartransmission located immediately to the rear of the clutch mechanism ora two-speed axle mechanism, said power means including a spring andvacuum operated double-acting motor the operation of which is controlledby the operation of a manually operated so-called four-way or doublethree-way selector valve and the operation of the accelerator of thevehicle in its control of the speed of the engine and the degree ofgaseous pressure within the intake manifold of said engine.

Yet another object of our invention is to provide, in a power plant ofan automotive vehicle, power means for moving, to one or the other oftwo positions, a gear shifting member of a changespeed transmissionmechanism said power means including a motor the power element of whichis connected to said gear shifting member by force transmitting means,including a yieldable means, having three distinct stages of operation,said power means being controlled by (1) the operation of a manuallyoperated four-way or double three-way selector valve, (2) the operationof the accelerator of the vehicle in its control of the speed of theengine, the degree of gaseous pressure within the intake manifold of theengine and its control of a switch constituting a part of means formomentarily disabling the ignition system of the engine, and (3) anignition interrupter switch actuated by means connected with the powerelement of the motor.

. v Yet another object of our invention is to provide,

, valve and (2) the operation of the accelerator of the vehicle in itscontrol of the throttle valve of the engine of the vehicle.

One of the important features of our invention is to provide adouble-acting pressure differential operated motor for establishing achange-speed transmission in one or the other of two settings said motorbeing connected with said transmission by means including a doubleactingyieldable means which is energized, that is cocked, during the firsthalf of the gear shifting movement of the power element of said motorsaid yieldable means being then operative, after said power element hascompleted its gear shifting movement to neutralize the transmission, toestablish the transmission in gear.

Yet another object of our invention is to provide power means foroperating the two-speed axle of an automotive vehicle said power meansincluding a double-acting vacuum motor comprising a casing memberdetachably secured to the casing of the two-speed axle and furthercomprising a power element operably connected to a shift fork orequivalent element of the axle mechanism. The force transmitting meansinterconnecting the shift fork and power element includes adouble-acting yieldable means which is of such a strength that the sameis cocked, that is the yieldable means is made a source of potentialenergy, when the vacuum motor is energized to efiect an operation of theaxle mechanism, said operation being effected prior to theneutralization of the axle mechanism which is effected during the lastpart of the movement of the power element of said motor, the cockedyieldable means then functioning, after the gears of the axle mechanismto be meshed are brought to synchronous speeds by controlling the speedof the engineof the vehicle, to expand thereby effecting a new settingof the axle mechanism.

Yet another object of our invention is to provide a simple, compact andeasily serviced double three-way or oft called four-way valve whichnected to the transmissionby iorcetranSm -tt n means operating in threedistinct stages toshift the transmission from one sle'ttirig toitheother, the operation of the power means being controlled by an operationof the throttle valve and a manually operated or controlled selectorvalve.

Other objects of the invention-anddesirable details of construction willbecome apparent from the detailed description of certain embodimerits ofthe invention-described in the specification; to frollowand disclosed inthe accompanying drawings in which:

Figurel is a diagrammatic view disclosing the preferred embodiment ofour. invention serving to .Qoperate a two-speed rear axle of anautomotive veh l Figure 2 is a sectional View disclosing the P Y1l andpressure difierential operated motor of that embodiment of our'inventiondisclosed in figural;

Figure 3 is asectional view ofthe. double threeway selector valve of.our invention;

Figure 4 is a View, similar to Figure-1, disclosing 'the mechanism ofFigure 1 modified to omit thevacuu m tank and-the torque controlling ig-.n t on disabl ech i Figure '5 is a sectional view disclosing the springand pressure differential operated motor ofthe mechanism disclosedinFigure 4; and

Figure 6 is,a sectional view disclosing details of'a two-speed rear axlemechanism, said mechanlsmbeing established in its low gear setting.

' R eierring now toFigure 1 disclosing one embodirnent of ourinvention arear axle, generally indicated by the reference numeral i0, is of thetwo speed type and the change from one axle speedto another: is effectedby means of a doubleactingdouble-ended spring and pressuredifferentialoperatedmotor !2" which may be secured to theaxle housing orany other suitable-mounting. It'is to be understood however that our-in-;ve'ntion is not necessarily limited "to means'for {operatin atwo-"Speed axle transmission mechanlsmpfor the double-acting motor 12 ofour in- ,Yem ion may also-be used to operate any multispeed transmissionmechanism i.e. the change gear transmission 13, to establish one or theother of two settings thereof.

Themotor =l-2 comprises a double-ended casing-H, FigureZ, and a-pistonthat is power elementlfithe latter being connected tothe axle-inechanism by a three-stage force transmitting -means-which constitutesan importantfeature of our invention.

At this juncture itis to be notedhoweverthat ,our invention is notlimited to the particular three-stageoperating force transmitting meansdisclosedin Figure 2 of the drawings; for itis wit r 1 in-the-purview ofour invention to coverthe force transmitting means including either adoubleacting torsion spring or the yieldable .meansof Figure of thepatent of EarlPrice N rmansd lmn 18 1. 4

I Referring now to Figure 2 the force transmitting means disclosedin-this figure includes a--rod 4 l8 slidably mounted in an end plate 20of the motor I2 said rod being operably connected at one of its ends toa crank 2|, Figure 1. This crank is preferably connected to a shifterfork l I, Figure 6, which is provided with pins I5 fitting .within agroove I! in a rotatable driving gear l9 :Qfi the'two-speed axle; In.-The geari I9 is meshed with a propeller shaft driven driving gear 3|;and the gear I9 is internally splined to mesh with the teeth of eitherone of two driven gear mem- ;hers123;,and;gidepending on the directionof the movement of the member 19. The gear member 23,constitutes..one;of a nest of gears, not shown, .pp'erative,,whenithemember I9 is meshed with lthe-'member,2,3',. .to establish the two-speedrear axle mechanism in its high gear setting and thel-memberz25=constitutes one of a nest of gears, not

shown, operative when the member I9 is meshed with the member 25, toestablish the two-speed axle mechanism in its low gear setting. No claimis made to-the-two-speed rear axle mechanism disclosed in Figure fi anditisto-benoted-as stated above, that this mechanism may beef-anyconventional design wherein a driving 'member actuatedbythe propellershaft of the vehicleis selectively connected with the driven partsof-the mechanism-to establish the transmissionmechanisrn orso-called-two-speedrear axle,-in one or the other of its gear ratiosettings.

- Continuing the description of the force transmitting meansinterconnecting the motor a l 2' and two-speed axle I8, a-hub portion'22of the piston IE is sleeved over the rod I8 and slidablethereon; andsaidhub 22 is operably connected to said rod by means of 'yieldablemeans of a certain strength. Inthat embodiment of our inventiondisclosed in Figure-=2 thisyieldable-means consists of two springs 24and 26' sleeved over the rod "I8 "said springs-preferably being of-equalor substantially equal strength. The spring 24, which constitutes a partofthe=f0rce transmitting -means interconnecting the piston 16 andtransmission, is interposedbetweenaflange portion '28 of--the-hub2-2 anda flange 3|] at the end of and fi'xedly-secured to the rod 18-. Thespring -26 isinterposed between a flange -32,-constituting a partof-thehub-ZZ, and the flangedend 33 of -a sleeve-member '34 said sleeveconstituting in effect-a portionof-the-rod I8. Movement of thesleeve-member to the-right,'Figure 2,; is prevented by a stop ring36-embeddedin the rod l8. Tubu- -lar members 38 and 40, fixedly securedat their outer endsto the end plates of the'motor casing, serve asstopmembers tolimitthemovement ofthe piston IGI -In that embodiment of ourinvention disclosed in-Figure l the operation of the motor'l2-iseontrolled-by (l) a four-way selector'valve 39, (-2) the throttleoperating accelerator M which in large measure controlsthe operation ofthem- -ternal com'bustion'engine 42 of the vehicle, (3) an acceleratoroperated ignition controlling switch' lfl'which is close'd'whenthe'accelerator is jfully depressed and '(4) an ignition controllingswitch -46,'-'Figure; 2 which-is actuated by the "rod 18; It is'tobe-noted here however, asis brought out hereinafter "in thisspecification, that the ignition controlling means of the -mechanis'mdisclosedjin-Figure 1 ;may be omitted; and the mechanism of Figure 1, somodified,=is disclosed in Figure 4. duplicate parts of the mechanism ofFigure 1 are identified by the same reference numerals with the additionof a prime.

Referring now to the four-way valve 39--dis- In the latter figure partswhich a hollow casing 41 provided with ports 48 and 50 connectedrespectively with ports 52 and 54 in the ends of the motor l2 by meansof conduits 56 and 58. The casing 41 is also ported at 60 to receive aconduit 9-2 connected to the intake manifold 64 of the engine. A vacuumtank 65 is incorporated in this conduit and a check valve 66 isincorporated in that portion of the conduit interconnecting the tankwith the manifold. This check valve insures the maintenance of therelatively low gaseous pressure within the tank when the accelerator isdepressed which operation increases the gaseous pressure in the intakemanifold. A spool shaped valve member 61 is slidably mounted within thecasing 41. A recess 68 of said member serving to interconnect the ports60 and 48 when the valve member is moved, by a manually operatedselector lever 63, to its high gear position said position of the valvemember being disclosed in Figure 3. The selector lever 63 is connectedby suitable means, not shown,-to a rod 69 which is preferably adjustablyconnected to the valve member 61.

When the above described high gear setting of the valve 39 is selectedby the driver then a compartment 10 of the motor 12, outlined by thepiston l6 and a part of the casin I4, is placed in air transmittingconnection with the intake manifold E4 via the conduit 62, check valve56,

vacuum tank 65, valve port 60, the recess 68, port 48 and the conduit55. At this time a compartment 12 of the motor is vented to theatmosphere via ports 14 in the valve casing 41, the interior of thevalve, port 50 and the conduit 58. It foldesired speed with thetransmission l0 established in its low gear setting. The driver will atthis time probably wish to effect the high gear setting in order toreduce the speed of the engine with the attendant saving of engine fuelandreduction of wear. Continuing the description of the operation ofestablishing the transmission in its high gear setting when the highgear setting of the valve 39 is effected the piston l8, as previouslydescribed, is subjected to a differential of pressures moving the sameto the left, Figure 2. It will be assumed that the driver at this timeis maintaining the accelerator at least partially depressed to maintainthe road speed of the vehicle and effect a partial vacuum in the intakemanifold. If the tank 65 were omitted the motor compartment 10 would bepartially evacuated despite the absence of said tank however byincorporating said tank and the check valve in the conduit 62 there isinsured a substantially constant source of vacuum to make possible anenergization of the motor I2 whenver the valve '39 is operated andirrespective of the position of the accelerator. The aforementioned highgear operation or setting of the valve 39 is what may be termed apreselecting operation, that is, the valve is operated prior to thehereinafter described operation of the accelerator. Now with thisoperation and the resultant vacuum energization of the motor l2, thereresults a compression of the spring 24 until the same is compressedsolid or substantially solid atwhichtime the end of the hub 22 is inabutment with a member 35 abutting the flange 30 and sleeved over therod 18; and this operation of the mechanism is apparent from anexamination of Figures 2 and 5 of the drawings. In other words thespring 24 is then said to be cooked that is potential energy is storedin the same. This cooking of the spring 24 is effected inasmuch as therod I8 is then held immobile due to the then existing driving load onthe teeth of the low speed transmission gears. With this spring cockingoperation, which may be defined as a first stage operation of the powermeans, the piston 16 moves to a position half way or substantially halfway between the inner ends of the stops 38 and 40 there being nomovement of the rod I8 for reasons explained above.

The driver, to complete the operation of establishing the transmissionin its high gear setting, will then release the accelerator to idle theengine thus developing a relatively high vacuum in the intake manifoldand also reversing the driving torque of the engine; and with thisoperation, with the resultant removal of the driving load upon the lowspeed gears of the transmission and subjection of the piston I 6 to arelatively high differential of pressures, there results a bottomingoperation of the piston that is said piston resumes its movement to theleft, Figure 2, to abut the stop 38. Now with this operation the rod [8is moved to the left by the relatively high power of the piston 16 toeffect the second stage operation of the power means the piston, rod andspring all moving as a unit; and this operation effects a demeshing ofthe low speed gears of the transmission, the transmission beingestablished in its neutral setting.

The third that islast stage of operation of the power means to establishthe transmission in its high gear setting is effected by an expandingoperation of the spring 24; and this operation takes place immediatelyafter the gears to be meshed have been synchronized. Thissynchronization will of course be effected when the engine and the forcetransmitting means interconnecting the same with the driving gear of thehigh speed gears have slowed down to a speed to make possible a meshingof said gears. It is to be noted that the force exerted by the spring 24to effect this high gear meshin operation is materially less than theforce exerted bythe piston IS in effecting the aforementioned secondstage, that is, demeshing operation of the mechanism. That this is trueis evident from the fact that the spring 2 3 is weak enough to becompressed by the force developed by the piston in effecting theaforementioned first stage operation of the mechanism. Now the latterforce is, by virtue of the partial vacuum of the intake manifold duringthe first stage operation, materially less than the force developed bythe piston during the second stage operation of the mechanism, that is,the force developed when the intake manifold is relatively high due tothe pumping operation of the engine pistons with the throttle completelyclosed. Accordingly, it follows, as stated supra, that the force exertedby the spring 24 in its gear meshing operation is materially less thanthe force exerted by the piston It in effecting the demeshing of thegears.

There is thus provided a pressure differential and spring operated powermeans, controlled by the accelerator and the valve 39, and operable toshift the transmission Ill from a low speed setting to a high speedsetting in three distinct stages of operation.

f7 fitter -the transmissionflzllnisrestablishedfirtits high=gear settingIthezdriverz-wili .thenkdepress Zthe accelerator: to i either:imaintain: or;.;incr.ease .Ithe road speed of thevehiclezaszdesired.

' Should the driverthen wishttorestablish the transmission. in' its low:gea setting :say to 1 iacilitate the operation of -passing':.lai car*zonthe road or to climb :a hill heneed butiop'erate"the valve 39 -toestablish thee same in tit i lowzgear "setting, andgwith the controlmechanism disclosed in the drawings, either release ior fully depresstheacccleratorg-the latterzoperationtbemg disclosed and claimed incurPatentiNoi 234805801, dated' AugustQOQ 1949-,aconstitutinga division -of"the instant application. -Wh'en-the:va;1ve 39 is placed in itslowgean-setting the compartment T2 --is placed in communication'with'the vacuum tank BS- and the compartment 'lll is vented-to theatmosphere; The piston Hi th'en movesto the *right, Figure 2, -to-"cockthat is compress 'the *spring 2-6 thereby completing-the I first stageof the -low'--gear operation of the transmission op---*-erati-ngmechanism. The-driver will then cont-inue' the operation ofestablishing the-transmission 1 in its lowgear setting by either fullyde- -pressi-ng the-"accelerator to close the: switch 44 Y -or byreleasing the-accelerator;either operation resulting-in a" reversal orthe' engine'torque. -If

the accelerator is fully' depressed, an" operation which the driverwould-'naturaily--efi"ect when:

ignition interrupter switch 46, Figure 2; which isclosed. when thetransmissionis established in itshigh'gearsetting that'is'w-hen the rodI8 is inits highgear position. When the trans- "missionisestabiished'inits" high gear setting the motor"parts"are--postionedas disclosed in"Figure 2.

A wire 82, leading from the switch46; is con- -nected tothe-"distributor 84 or the'conventional ignition systemofthe engine; allas is'disciosed in-Figure 1. lt-followsthat When-the switches 44 and arebothclosed the primary winding-8| of the ignition-coil 86 is groundedthereby 'diswabling the-ignition system. This disablingng of theignition system disables the engine 'and'reverses the "driving-torqueupon the high speed gears of the transmission; and this operation makespossible thesecond stage operation" of the power means'that isthe-bottoming movement of-the pistonleand the concurrent movement oftherod 1 8 to'the right to neutralize the trans mission. The motor I2 isat this time vacuum energized'to eiTect this operation by virtueof theinclusion in the vacuum system of the check valve 66 and the vacuumstorage tank 65; for if the tank were not incorporated in the vacuumi'Asto. the third stage ct' operation ofthe-power r means: to eiT ectvthemeshing of the low-speed 'gears or the-transmission thisoperation-ofsaid opower means is effected -when= the -engine has beenspeeded upsufliciently to effect the-neces- 'sary synchronizationof thelow speedgears. -'TThise operation is quickly effected inasmuch as r itris toiberemembered .that the' throttleis at this timewidetopen.

.zIfthe driver wishes' to efiect the low gearsetting of the'transmissionwithout disabling the big-nition system =he need but firstplace the valve -39ain its -low gear-setting, then release the ac'cel-:teraton and lastly-depress the accelerator to speed iuptheiengi'ne. Theabovedescribed three-stages cof operation ot-the: power means istheneffected zinasmuch asthis operation of the valve resultsin thecocking 0f 1 the spring I 2 6 which constitutes the firststageoperation, the reversarofthe engine torque by the release of theaccelerator effects the d'emeshing of the high-speed gears :toneutralize the transmission; said operation constituting thesecond.stage operation, and t-he subsequent depression of theaccelerator' tospeed TLup? the engine effects the' necessary synchronizationiof the lowspeed gears to make possible the above described third stageof operationthat is thetexpan'sion of the-spring: 26:to effect thelow gear operationof the transmission.-

Thereris thus f provided a 'verysimple yet" effii'zcient three=stagetransmission operating 1 mechanism controlled' by the accelerator andaselector valve and operating to "establish one or the other of 'twosettings of a change-speed transmission mechanism irrespect'ive" of""where said mechanism is incorporated-in the"=pow'er'pla"nt Ioftheive'hicle. Ifthe torque-controlling ignition "disabling mechanism' isnotdesired-th'en-theelectricalemechanism and the:yieldable means in theaccelerator operated rod may be omitted. The tank= 565 m'ay:then also beomitted all as is" dis- 'closed sin Eigures 4--and- 5' of "the drawingshowever it is desirable to include the check valve GS inasmuch''assuch:-'a valve will insure sufti'cient "vacuum to maintain the spring'26 cocked when the "accelerator is depressed in the operation "ofefiectingithe secondrg'ear setting of" the trans- :mission:

7 In "conclusion it is to be stressecl' that the heart 1 of ourinvention r lies in the 1 construction -a'n'dl arrangement of 1 the 1motor I'2 and the r force "transmitting f means, particularly theyieldable "*means, interconnecting the" power element of said motor'with the transmission; This .yieldable means; 'which c'ooperates-with'th'e s'olid members I8, 31] and trand isin seri'es 'with the powereler'nent in said force transmitting :mea'ns'; is of such a strengththat its condition is changed, i that isp'otential energy E is storedtherein," when the selector valve is I operated; "and the strength 0fsaid yieldable means is such 'that this "potential energy s'torin'goperationconstitutes-the first of 'three stages A cf oper'ation of P theaforementioned force' transmitting means. With the shifter-mechanism of'our invention the trans- -mission 5 is "operated quickly andquietlythere being :no clashing-of gears; furthermore the control of "the'mechanism is so simple thatit is v submitted that the entire operationis practica'lly fool proof.

It is thought that' the invention and-m'any of its attendant-"advantageswill 'be understood from the forego'ing description and it will 1 beapparent that various changes may be "m'ade' in the form; constructionanearrangementbf the parts without departing from the spirit and scopeof' the invention or sacrificing all of its material advantages, theforms hereinbefore described being merely preferred embodiments.

We claim:

1. In an automotive vehicle provided with a change-speed transmission,an internal combustion engine and a carburetor for in part controllingthe operation of the engine, said carburetor including a throttle valveoperative in part to control the degree of gaseous. pressure within theintake manifold of the engine and to control the speed of the engine;power means for operating said transmission comprising a double-actingpressure differential operated motor having a power element operablyconnected to the transmission, a selector valve for controlling theenergization of said motor, air transmitting means interconnecting theintake manifold of the engine, the selector valve and the motor, and adouble-acting three-stage operating force transmitting means connectingthe aforementioned power element 'with the transmission, said forcetransmitting means including a rod connected to the transmission andfurther including yieldable means of a certain strength concentricallymounted with respect to and abutting a portion of said rod, said forcetransmitting means being so constructed that with an operation of theselector valve there results a vacuum energization of the motor toeffect one of the stages of operation of the force transmitting means,that is, a compression of the yieldable means, another stage ofoperation of said force transmitting means being then effected by aclosing of the throttle valve to reduce the torque of the engine and yetanother stage of operation of said force transmitting means beingsubsequently effected when the engine speed is such as to effect asynchronization of the transmission gears to be meshed.

2. In an automotivevehicle provided with a change-speed transmission, aninternal combustion engine and a carburetor for in part controlling theoperation of the engine, said carburetor including a throttle valveoperative in part to control the degree of gaseous pressure withintheintake manifold of the engine and to control the speed of the engine;power means for operating saidtransmission comprising a double-actingpressure differential operated motor including a power element and acasing, a selector valve for controlling the energization of said motor,air transmitting means interconnecting the intake manifold of theengine, the selector valve and the motor, and force transmitting meansconnecting the aforementioned power element with the transmission, saidforce transmitting means including a member secured to the hub portionof the power element, a member operably connected with the transmissionand double-acting yieldable means of a certain strength sleeved oversaid first mentioned member and serving to interconnect said twomembers; the parts of said force transmitting means being so constructedand arranged and so operative that with an operation of the selectorvalve to control the operation of the motor and a subsequent operationof the throttle valve to control the torque of the engine and degree ofgaseous pressure in the manifold there results an operation of the forcetransmitting means in three distinct stages in the operation of thepower means to effect a change of setting of the transmission.

3.'In an automotive vehicle provided with a. change speed transmission,an accelerator, an internal combustion engine and a carburetor for inpart controlling the operation of the engine,

said carburetor including an accelerator operated throttle valveoperative in part to control the degree of gaseous pressure within theintake manifold of the engine and to control the speed of the engine;power means for operating said transmission comprising a pressuredifferential operated motor having a power element operably connected tothe transmission, a valve for controlling the operation of said motor,air transmittingmeans interconnecting the intake manifold of the engine,the control valve and the motor, and force transmitting means connectingthe power element with the transmission, said force transmitting meansincluding a plurality of solid members and further including yieldable:means connected in series with said solid members, said yieldable meansbeing of such strength that the same maybe compressed solid orsubstantially solid by a. force which is less than the force developedby the power element when the control valve is operated to effect anenergization of said motor, the engine throttle at the time being openedby the accelerator to effect an engine speed greater than engine idlingspeed; the partsof the transmission operating power :means being soconstructed and arranged and so operative that the force transmittingmeans is operable in three distinct stages to effect an operation of thetransmission, the first of said stages serving to effect theaforementioned comwhen the accelerator is depressed to open thethrottle, the second of said three stages of opera 40..tion of theforcetransmittingmeans serving to neutralize the transmission mechanism,said operation being effected when'the accelerator is released to closethe throttle thereby reversing the engine torque, andthe third of saidthree stages 4520f. operation of the force transmitting means serving toestablish the transmission in gear, said operation being efiected by theexpansion of the yieldable means after the gears of the transmission tobe meshed are synchronized.

- 4. In an automotive vehicle provided with a change'speed transmission,an accelerator, an internal combustion engine and a carburetor for inpart controlling the operation of the engine,

said carburetor including an accelerator operated throttle valveoperative to in part control the degree of gaseous pressure within theintake manifold of the engine and to control the speed of the engine;power means for operating said transmission comprising a double actingmotor, re-

=sponsiveto differential fluid pressure in both directions of itsmovement, said motor having its power element operably connected to thetransmission, a selector valve movable to one or the other of twodifferent positions to control the operation of said motor, airtransmitting means interconnecting the intake manifold of the engine,the selector valve and the motor, and force transmitting meansinterconnecting the power element of the motor with the transmission,said force transmitting means comprising a member directly connected tothe transmission and further comprising means, including yieldable meansand solid members interconnecting said member with the power element ofthe motor, said yieldable means being of such strength that 11' the samemay be compressed-solid or. r substantially solid'bv aforce which isless than the force developed by the power element whentthe selec-r torvalve is operated to effect anl'energization of; said motor ,theenginethrottle at the time being 5,; opened by the accelerator to: effect anengine speed'greater than engine idling speed; the parts of thetransmission operating power means being so constructed and arranged andso operative that the force transmitting means is operable 11'1"l()lthree distinct stages'toefiectanoperation of the l transmission, thefirst of said stages serving. to effect the aforementioned compressionof the. yieldable means, said-operation being effected, by anenergizati'on of the motor, when theiselector 15 i valve is operated atatim'ewhenthe. accelerator is' depressed to-open thethrottle, the secondof? said three stagesof operationof. the force transmitting means being:completed when'the power T. element is bottomed within the motor, saidope era'tion servingto demesh. the: transmission: mechanism and beingeffected when the accelerae tor is released to close the throttlethereby'revers-fing the engine torque, and the third of said threestages of operation of'the force transmitting '25 means serving toestablish? the transmission in" gear, said operation beingfeffected'bythe expana sion of the yieldable means aft'er the gearsof thetransmission tobe meshedare synchronized, the latter operation'beingeffectedby a control'of the-" speed of the engine.

5.A double acting pressure differential operated motor: adaptedfonusee'ini an automotive transmission operating mechanism said .motorcomprising a double'ended 'cylinder member, a"35,- power elementreciprocable within the. cylinder member, a force transmittingtransmission 'operating rodsli'dably mounted within the power' elementandslidably mountediin one end of the cylindermember, a flangeimember'mounted on 40 one end of the rodasecondfiange member also mountedonsaid rodf aifo rce transmitting yieldable member interposed between oneface for the power element and 'one of said'fiange members, anotherforce transmitting-yieldable member in 45, terposed between the otherface of the power element and the other tof saidiflange members;

a stop membersecured. to one end of the cylinder said member serving "asa'stoptfor the powerv 1 element whencthesame is power operated .in onedirection of its movement, and azsecond'stop member secured to the otherend of the cylinder said stop membertiserving as ai=stoptforthe powerelement when ithefisame Tis power .'oper-'- ated intheoth-er'directionrof'its movement.

6. A double acting pressure ldiiferential oper-i ated motor'adaptedlforuse in an automotive transmission operating mechanism saidmotor 1* comprising a double ended cylinder :m ember, a power elementreciprocable within thecylinder" 12 member; a force transmittingtransmission.- operating. rod;slidably mountedwithin the power elementand-x-slidably'mounted in-one end of the cylinder member; a--fiangemember mount.-v ed on one end of the rod, a second flange memberalsomount'ed ons' said rod, a force transmitting yieldable member sleevedover the rod and-interposed between one face of the power element andone *of said flange members, another" force transmitting. yieldablemember sleeved over the rodandinterposed between the other face of thepower. element. and the other of said flange members, a stop membersleeved over the rod-and secured to-oneendOf the cylindersaidmemberx'servingfasa stop for the powern'element when :the same :is.IDOWGI' operated in onev directioniofzits movement, and a secondistoprmember. :sleeved over. the-rod and secured to the r'other"endiof :the cylinder said stop member serving as :a stop for the powerelement when? the same 'isfpower .operated in the other direction' ofits' movement.

7. In actuating meansforashiftable gear ra tio.Jselecting"memberpasupporting member, a'

reciprocableforkiishi'fting rail mounted on said supporting-"member, areversibly operable power aetuatedcmemhen'means limiting travel of saidpower actuatedmemberto a predetermined distance in-either direction;"and connecting means between said power "actuated/member and rail totransmit controlled 'forcesof difierent magnitudes in' immediatesequence'to said rail, includingmeans car-riedby'therail renderedeffective :duringimovement of said power actuated member in eitherdirection and operable after conclusion of said-tmovement of said poweractuated member torapplyafinal reduced force to :continue'movement oftherail in said direcion;

ALBERT E. WILSON.

HENRY D. HUKILL.

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